Fluid operable apparatus



Feb. 6, 1951 w. D. BERKLEY D OPERABLE APPARATUS WARREN D. BERKLEY ii/ W ATTORNEYS Feb. 6, 1951 w. D. BERKLEY 2,540,235

FLUID OPERABLE APPARATUS Filed Dec. 13, 1946 4 Sheets-Sheet 2 INVENTOR v WARREN D. BERKLEY Y ATTORNEYS Feb. 6, 1951 w. D. BERKLEY FLUID OPERABLE APPARATUS 4 SheetsSheet 3 Filed Dec. 13, 1946 INVENTOR WARREN D. BERKLEY v BY ATTORNEYE Feb. 6, 1951 w. D. BERKLEY FLUID OPERABLE APPARATUS 4 Sheets-Sheet 4 Filed Dec. 13, 1946 FIG? TYB

INVENTOR WARREN D. BERKLEY ATTORNEYS Patented Feb. 6, 1951 FLUID OPERABLE APPARATUS Warren D. Berkley, .Dayton, Ohio, assignor to H-P-M Development Corporation, Wilmington, Del., a corporation of Delaware Application December 13, 1946, Serial No. 715,925

' 3 Claims. (01.103-126) sun another object of this invention is to.

provide a gear pump or motor which is easily maintained in efiicient operating condition. y

A still further object is to provide an improved design for a gear pump or motor in which the several parts of the unit may be easily manufactured to within the close tolerances permitted for this type of equipment.

A further object is the provision ofa gear pump adapted for being operated in either direction and having means for continuously drawing the leakage fluid from the pump casing into the main flow channel therethrough.

These and other objects and advantages will become more apparent uponreference to the following description taken in connection with the accompanying drawings in which:'

Figure 1 is a side elevation of a pump constructed according to this invention; I

Figure 2 is a transverse section therethrough indicated by the line .2-2 on Figure 1;

Figure 3 is another transverse section and is indicated by the line 3-3 on Figure 1; v

Figure 4 is a longitudinal section and is indicated by the line 44 on Figure 2;

Figure 5 is a plan section indicated by the line 5-5 on Figure 4;

Figure 6 is an exploded perspective view showing the several parts of the unit in partially assembled condition;

Figure 7 is a transverse section through a modifled construction; and

Figure 8 is a plan section indicated 8--8 on Figure 7.

Referring to the drawings,-a pumping unit according to this invention comprises a pair of pumping gears l0 and 12 which are rotatable within a cylinder block [4. The block I4 comprises the cylindrical recessesl6 and 18 which closely receive the gears IQ and i2, respectively, and also has the cut-out spaces '20 and 22 therein in the plane at which the gears mesh for the by the line purpose of permitting fluid flow to and from the 7 said gears.

One of the gears, as for example the gear 10, is keyed to a drive shaft 24 while the other of the said gears is mounted on a shaft 26. and need not be keyed thereto. Preferably,the said gear is pressed on the shaft in order to facilitate the journaling thereof within the pump.

As best seen in Figures 4, 5 and 6, the cylinder block I4 is abutted on either side by the end plates 25 and 30 of the pump. These plates are doweled to the vcylinder block as by the dowel pins 32 and are retained in position by a plurality of cap screws 34. It will be understood that the cap screws 34 could be replaced by through bolts if desired in order to eliminate the tapping of the cylinder block for the cap screws.

As seen in Figure 4, the shaft 24 to which the gear H3 is keyed, extends through the end plate 36 into position to be engaged by a drive motor when the unit is used as a pump, or to be connected with a driven member if the unit is to be usedas a motor. There is preferably an oil seal as indicated at 36 in the end plate 30 through which the shaft extends so that there is no leakage of oil to the outside of the unit during operation.

While the shafts 24 and 26 may be journaled in any of several well-known manners, it is preferred to use the needle type roller bearings which are indicated at 38 and which are placed in suitably machined recesses in the end plates 28 andtii. The recesses which receive the hearings in the end plate 30 are connected by a cored passage means at which is best seen in Figures 4 and 5, and which communicates with the spaces 20 and 22 in the cylinder block through the check valves 42 and 44, respectively, these check valves opening from the recess 48 so that whichever side of the pumping unit is the suction side will continuously withdraw the leakage fluid which accumulates in the said recess.

The end plate 28 is adapted for receiving the conduits 46 and 48 by means of which fluid'is conducted to and from the pumping unit. The conduit 46, as seen by the dotted line construction in Figure 3, communicates with the space 20 in the cylinder block it by means of a cored passage in the end plate 28. Similarly, the conduit 48 communicates by the cored passage shown in Figure 3 with the space 22 in the cylinder block.

As will be noted in Figures 4-, 5 and 6, the axial length of the gears l0 and i2 is less than that chined and fit closely between the gears and the end plates and within the cylinder block. By means of these wear plates, the cylinder block and end plates may be machined with flat surwill induce wear on the cylinder block.

faces thereon so that exceedingl close tolerance limits may be observed in the manufacture of the unit.

Furthermore, any side thrust on the pumping gears is carried entirely by the wear plates so that there is no wear on the cylinder block or end plates, and, after a predetermined period, the wear plates can be replaced to bring the pumping unit into its original operation condition. It will be observed that the Wear plates could be constructed of a suitably wear resistant material different from that of the-cylinder block and end plates if so desired.

As the gears l and i2 rotate in order to transfer fiuid between the spaces and 22 in the cylinder block [4, the tooth spaces in the pumping zone have fluid entrapped therein'by the tooth of the gear in engagement therewith. If this pressure is not relieved, it will lead 'to high separating thrusts on the pumping gears which For relieving this pressure, the wear plates 50 are provided with the channels 52 therein which may,

as shown, comprise cylindrical recesses which extend over the zone within which it is desired to relieve the entrapped fluid. One of these is provided in each wear plate so that regardless of the direction of rotation of the pump, the

aforementioned entrapped fluid is relieved.

While any suitable mounting means may be provided for the-pump, the arrangement illustrated in the drawings'includes the foot member -54 which is preferably cast integrally with the end plate and by means of which the unit may be mounted on a mounting pad provided on a machine part or a suitable base member.

Modification of Figures 7 and 8 Figures 7 and 8 illustrate a slightly modified construction-and similar parts in these figures are correspondingly numbered with the addition of a subscript a.

In these views, the porting for the fluid flowing *to and from the pumping unit is entirely in the cylinder block [4a and both of the conduits extend'into the cylinder block from one side thereof. The lower of the conduits communicates in substantially a straight line with the pumping zone of the gears I00. and Ho and the upper of the conduits communicates with the pumping zone on the opposite side of the gear through a passage 55 cored in the cylinder block and extending around the upper gear Hid.

As will best be seen in Figure 8, this type of porting enables both of the end plates 28a and 30a to have check valves opening from the cavities thereof so that the leakage fluid can continuously be drawn into the cylinder block. Still another advantage which obtains from the port- "ing shown'in Figures '7 and 8 is that the drive shaft 24a can be made double ended if desired for th purpose of operating a plurality of elements from a single drive motor.

Operation In operation, letit be assumed that the gear I0 is driven in the clockwis direction, as viewed in Figure 2. As the gears l0 and i2 rotate, fluid is drawn in through the conduit 48 and recess 22 into the tooth spaces in the gears and carried around thereby until the said spaces communicate with the recess Zll in the cylinder block. Thereafter, as the teeth of each gea-I mesh with the tooth spaces of the other, fluid is displaced from .the'spaces and discharged from the pump through the conduit 46. As the teeth move into the spaces, they reach a position wherein they make contact with both sides thereof and thereby entrap fluid beneath the bottom of th tooth space and the top of the tooth therein. This entrapped fluid is relieved through recess 52 which, as seen in Figure 2, communicates with the'said tooth space until it reaches a minimum volume.

If, during the operation of the pump there is a leakage of pressur fluid to one side of the gears, they are thrust to the side against one of the Wearplates. The wear which then takes place inconfinedto the side of the gear and the surface ,of the wear plate and this is maintained at a minimum by constructing a wear plate of a :goodbearing bronze.

.Also during the operation of the pump there will be a leakage of fluid through the bearings thereof into the cavities in the end plates. This fluid is continuously drawn into the suction side 'of the pump from at least one of the said cavities .isthat pumping units ,ofdifierent size can readily bemademerely bychangingthe gear size, the shaftlength, and the axial length of the cylinder block. This permits the quantity production of the endplates andwear plates with a subsequent reduction-in the individualexpense of each piece.

. It .will be understood that this invention is susceptible tomodification in. order to adaptit to diiferent usages and conditions and, accordingly, it is desired to comprehend such modifications within thisinventionas may fall within the scope ofthe appended claims.

I claim:

1. In a gear pump or motor; a cylinder block; a pair of pumping gears closely received within said block while in mesh; shafts supporting said gears; end coversfor said block rigidly secured thereto and having bearing wells into which said shafts extend; a pairof identical wear plates receivable; in said block and closely fitting between said gears and'said end covers, said wear plates and said block'being adjacently recessed to define high and low pressure chambers on opposite sides of the meshing zone of said gears; channel means formed-in at least one of said wea plates adjacent the meshing zone of said gears for maintainingthe toothspaces of said gears in com munication with one ,of said chambers during at least-a part of the travel of, said spaces through said zone; and a plurality of passageways connecting saidbearing wells with said chambers,

said passageways including check valves opening toward-said chambers.

,2. In a gearrpump org-motor having a pair of meshing pumpinggears rotatable within a cylin- .der block-shaftsisupporting said gears and end coverssecured to opposite faces of said block and having bearing wells" into which said shafts ex- -;.tend; a wear ;p1ate-in each end of said cylinder fine high and low pressure chambers on the opposite sides oftthe=-meshing.zone of said gears;

portions of said gears; a pair of flat wear plates.

disposed on opposite sides of said gears, each of said wear plates being formed on one side thereof with a recess to define with said cylinder block high and low pressure chambers located to either side of the meshing zone of said gears; end covers secured to the opposite faces of said cylinder block, said end covers being formed with bearing wells for the reception of bearings for journalling the shafts on which said gears are supported; passage means formed in at least one of said end covers and connecting the bearing wells thereof with each of said chambers; and check valves in The following references are of record file of this patent:

UNITED STATES PATENTS in the Number Name Date 1,436,263 Johnson Nov. 21, 1922 1,781,619 Wendell Nov. 11, 1930 1,927,395 Edwards Sept. 19, 1933 1,976,227 Howard Oct. 9, 1934 2,082,412 Morton June 1, 1937 2,210,152 Sacha Aug. 6, 1940 2,260,809 Johnson Oct. 28, 1941 2,281,157 Kanuch et a1. Apr. 28, 1942 2,292,331 Vertson Aug. 4, 1942 2,344,628 Monahan Mar. 21, 1944 2,395,824 Herman Mar. 5, 1946 2,412,588 Lauck Dec. 17, 1946 2,413,081 Shaefier Dec. 24, 1946 2,420,622 Roth et al. May 13, 1947 

